binutils-gdb/gdb/testsuite/gdb.ada/str_uninit/pck.adb

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-- Copyright 2011-2017 Free Software Foundation, Inc.
Internal error trying to print uninitialized string. Trying to print the value of a string whose size is not known at compile-time before it gets assigned a value can lead to the following internal error: (gdb) p my_str $1 = /[...]/utils.c:1089: internal-error: virtual memory exhausted. What happens is that my_str is described as a reference to an array type whose bounds are dynamic. During the read of that variable's value (in default_read_var_value), we end up resolving dynamic types which, for reference types, makes us also resolve the target of that reference type. This means we resolve our variable to a reference to an array whose bounds are undefined, and unfortunately very far appart. So, when we pass that value to ada-valprint, and in particular to da_val_print_ref, we eventually try to allocate too large of a buffer corresponding to the (bogus) size of our array, hence the internal error. This patch fixes the problem by adding a size_check before trying to print the dereferenced value. To perform this check, a function that was previously specific to ada-lang.c (check_size) gets exported, and renamed to something less prone to name collisions (ada_ensure_varsize_limit). gdb/ChangeLog: * ada-lang.h (ada_ensure_varsize_limit): Declare. * ada-lang.c (check_size): Remove advance declaration. (ada_ensure_varsize_limit): Renames check_size. Replace calls to check_size by calls to ada_ensure_varsize_limit throughout. * ada-valprint.c (ada_val_print_ref): Add call to ada_ensure_varsize_limit. Add comment explaining why. gdb/testsuite/ChangeLog: * gdb.ada/str_uninit: New testcase.
2014-12-08 16:37:00 +01:00
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
package body Pck is
procedure Do_Nothing (A : System.Address) is
begin
null;
end Do_Nothing;
function Foos return String is
begin
return "string";
end Foos;
end Pck;